If you are new to living afloat, And have any dependents, I strongly recommend you to buy your new home already on an established residential mooring. This means the mooring has planning permission for residential use and you have official residents status at that address, essential for bank accounts, driving licence, benefits etc.
If you are continuously cruising or on a mooring that doesn't have residential planning permission, there may be many others living on the same mooring and it is worth asking their advice as to the local situation and how things happen in that area. If you have family responsibilities, a mooring with residential planning permission has to be favourite.
(ESSENTIAL for a STATIC houseboat is a long leasehold OR Freehold Mooring.
Many lives have been shattered when their static (= unpowered) houseboat has been told their rented mooring is no longer available.
These moorings are disappearing fast due to development and you have no protection as you would in a house or caravan.
It then cost many of them thousands of pounds to have the boat towed away and broken up for scrap. Study the mooring agreemant and imagine the worst case scenario - THAT is the risk you are taking. The true valuation of a Static houseboat WITHOUT a long leasehold OR Freehold Mooring is the scrap value of the weight of metal, less the cost of towing away and breaking up plus what you can get on ebay for any re-saleable contents. ) NEVER buy any houseboat without an "Out of the Water Survey" If that costs too much (get a quote first) Then it will cost too much every 4 years for maintenance and insurance survey.